Cheryl Rofer is a chemist, retired from Los Alamos National Laboratory, where she managed the environmental cleanup of MDA M and other sites and helped to develop detection and remediation technologies. She blogs at http://phronesisaical.blogspot.com/

As the old plutonium plant at Technical Area 21 comes down, the Department of Energy has an opportunity to clear up a continuing question: How much plutonium got stuck in the pipes?

Every year or so, a report on plutonium accounting is released by the government. This is a sporting subject for the media, because there is inevitably a discrepancy and one alarming possibility is that the plutonium must have made its way into terrorists’ hands. Or perhaps the material is being hidden away for no-good purposes or is residing in the reservoir from which you get your drinking water.

The discrepancies tend to be within the bounds of accounting errors plus the material that, in any processing operation, gets stuck in the pipes, otherwise known as material unaccounted for (MUF). We can guess from the experience of other industries how much gets stuck in the pipes, but, with the demolition of the Cold War weapons plants, we can actually measure it.

Rocky Flats, the old nuclear weapons production site in Colorado, is no more. The gaseous diffusion plants at Oak Ridge are being taken down. The DP site in TA-21 is next. The disposal sites that receive the material from the demolished buildings have requirements for the types and amounts of radioactive and hazardous materials they can receive; it’s part of their license.

Preliminary cleanups at all three sites have removed some of the plutonium and enriched uranium. Worker safety from both ingestion and criticality hazards requires such precautions. Accountability for special nuclear materials is another motivator.

So the cleanups must be producing numbers for that MUF. The numbers are necessarily approximate, but they will be better than the guesses.

I’ve tried to get the numbers for Rocky Flats. Searching the Web in multiple ways doesn’t give anything. I’ve asked people who might know, and they don’t. Recently, Frank Munger, a reporter at the Knoxville News, was wondering about the K-25 diffusion plant. He finally got a response from the DOE: those numbers are Official Use Only.

Official Use Only isn’t a particularly high level of classification and could be rescinded by any number of DOE personnel. Releasing those numbers would produce a flurry of interest in the media and blogosphere, some of it unfavorable. But the transparency (and probably the numbers themselves) would improve DOE’s credibility. So remove those OUO markings, DOE, and let us know. You could even release a weekly or monthly tally as DP and K-25 come down.